$ { {-5} \times \left[\begin{array}{rrr}{3} & {0} & {4} \\ {2} & {0} & {-2}\end{array}\right] = {?} } $
Solution: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-5}\times{3} & {-5}\times{0} & {-5}\times{4} \\ {-5}\times{2} & {-5}\times{0} & {-5}\times{-2}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-15} & {0} & {-20} \\ {-10} & {0} & {10}\end{array}\right]}$